The USAAF Looks for Something Better than a C-47

Loading a Jeep into this RAAF C-47 shows it wasn't ideal for large or bulky loads.

During the interwar period of the 1920s, US military air transport was modest at best and consisted primarily of "off the shelf" civilian designs that were modestly modified with things like reinforced cabin floors and wider doors but were essentially airliners without seats. Until 1934, for example, the US Navy and Marine Corps relied on Ford Trimotors for transport! The arrival of the Douglas DC-2 offered a big improvement in capability for the US military. With war clouds looming in Europe and Asia in the 1930s, the US Army Air Corps went about looking for something better than adapted DC-2s. Bids were requested and Douglas offered an attractive proposal for upgraded DC-2 aircraft better tailored to military transport operations. Not long after, General Henry "Hap" Arnold became head of the USAAC (which later became the USAAF) and being a personal friend of Donald Douglas, was well aware of a DC-2 upgrade in the works that was the result of a marathon telephone conversation between Donald Douglas and the head of American Airlines, C.R. Smith. That aircraft was a leap in performance and capability over the DC-2 and at the time was called the Douglas Sleeper Transport (DST). In due time, of course, the DST became the DC-3 but General Arnold saw the DST's design and performance as an ideal basis for a transport. Army officials met with the designer of the DST, Arthur Raymond, and the C-47 was born. When the war finally broke out with the German invasion of Poland in September 1939, the C-47 wasn't yet in production and suddenly the branches of the US military needed air transport aircraft. The C-47 Skytrain (Dakota in RAF service) made its first flight on 23 December 1941 as Douglas embarked on a major facility expansion to meet the demand for the C-47. At production peak in May 1944, the company was building just under 19 C-47 aircraft each day! Despite the massive expansion and number of C-47s needed, the Army did have several issues with the C-47 but it was the best aircraft available at the time. There were three main issues the Army had- the first was that the tailwheel configuration and side cargo door made it difficult to load large items. Secondly, the maximum payload was too light as it was based on the maximum civilian load for the DC-3, and thirdly, the Army felt that as it was a DC-1/DC-2 derivative, it was old technology. With the United States now in the war, the Army thought that aluminum production was best used for armed combat aircraft and that cargo aircraft which operated in support roles ought to use non-strategic materials. While there was never a formal competition for a C-47 replacement but rather a series of issued requirements, quite a bit of money was spent over the course of the war to develop a transport that was better than the C-47. 

Budd C-93/RB-1 Conestoga

At the outbreak of war, several aircraft made out of the non-strategic materials made the first attempt at replacing the C-47. The first came from the E.G. Budd Company of Philadelphia- they had developed the shotweld technique for joining two pieces of metal- it used a short burst of electrical current to bond two pieces of metal. Invented in 1932 by a Budd engineer, shotwelding was used on the products Budd was known for- railroad cars and road vehicle bodies made of stainless steel. In discussions with the US Navy, Budd hired an aeronautical engineering staff to design a shotwelded (therefore no rivets) transport that would be made of readily available stainless steel. The Navy ordered 300 to be designated the RB-1 and the Army ordered 600 to be designated the C-93. Though made primarily of thin-gauge stainless steel, the wing aft of the spar and the moving surfaces of the tail were fabric covered to offset the weight of the steel. 

The design of the Conestoga was radical for the day and set the pattern for an efficient military transport even to this day. A high mounted wing allowed for an unobstructed main deck with a tricycle landing gear to keep the main deck level and low to the ground to ease loading. An aft loading ramp/door allowed rolling stock to be driven on/off of the aircraft. The flight deck sat up above the main cargo deck to maximize the cargo volume of the fuselage. In addition, there was an integrated hoist in the cargo deck to ease loading an locations that lacked ground equipment. The first flight was on 31 October 1943 and three prototypes conducted the flight test program. Using the same engines as the C-47, the Conestoga was underpowered and possessed sluggish handling- pilots joked that for a plane made by a railroad car company, it sure handled like one! By time time cost overruns and construction delays were resolved at the Budd factory, aluminum production had vastly increased in the United States and the need for an aircraft made of non-strategic materials diminished. The Army canceled its order for the C-93 and the Navy reduced its order from 300 to just 25. Just 17 RB-1s were delivered to the Navy by March 1944 and that small number served primarily as hacks for naval air stations. With such a small number in the fleet, the Navy found the RB-1s uneconomical and sold them off as surplus in early 1945 before the war even ended. Twelve Conestogas were purchased by a new cargo operation, National Skyways, that was founded by a group of pilots that had once served with the American Volunteer Group in China. National Skyways would later change their name to Flying Tigers- but that's a story for future blog article!

Curtiss C-76 Caravan

Another aircraft from the Army's concerns in 1941 that was a contemporary of the Budd C-93/RB-1 Conestoga was the Curtiss C-76 Caravan. The company was engaged by the Army that year to build a transport aircraft that like the Conestoga, would not only be made out of non-strategic materials but also exceed the performance and utility of the C-47. The Caravan was designed by the chief designer at Curtiss, George Page, who was also responsible for the C-46 Commando. While the Conestoga would be made of stainless steel, Page elected to use wood for the Caravan but interestingly, the only high performance aircraft at the time in production made from wood, the De Havilland Mosquito, wasn't used as a source of expertise. De Havilland used a layered plywood construction using a lightweight balsa wood core that made the Mosquito strong but light. Curtiss engineers instead favored mahogany in layers- being a much denser wood than what was used on the Mosquito, the Caravan soared in weight. Despite this, the Army helped Curtiss secure large stocks of mahogany and a number of furniture manufacturers were set up as component subcontractors with final assembly at Curtiss's new plant in Louisville, Kentucky. 

Much like the layout of the Conestoga, the C-76 Caravan featured a retractable tricycle landing gear to keep the main deck level. It also had a high wing layout for an unobstructed main deck hold and also put the flight deck above the main deck. Instead of an aft loading door and ramp, the Caravan had a swing nose that opened to the side ahead of the flight deck. The prototypes were built at existing Curtiss facilities in St. Louis as well as the new Louisville plant with the first flight on 3 May 1943. The flight test program was a disaster. The aircraft, using the same engines as the C-47 but made of dense mahogany, was woefully underpowered with a cargo payload not much more than the C-47. On the first flight, the aircraft vibrated so badly the flight test crew made a hasty return to the St. Louis Lambert Field. On the second test flight, the prototype literally shook itself apart with the loss of the pilots. In addition, when empty, the Caravan had to be ballasted to maintain its center of gravity- amusingly, the ballast needed to maintain an empty load CoG was more than the maximum payload! The control surfaces suffered from buffet and even shook while the plane was on the ground if it was windy. The wing spar failed load testing eight times, only holding up to 40% of the predicted maximum load. The Army wasn't pleased and was more than happy to cancel their order for 175 C-76s, particularly as aluminum production had vastly increased as the war progressed. Only 14 aircraft were built and most spent their days as ground instructional airframes. 

Wind tunnel model of the Waco C-62

There was a third aircraft that stemmed from the Army's 1941 call for something better than the C-47, but it never flew. Waco Aircraft had been building both training and assault gliders for the military and they tendered a design that received the designation C-62. Like the Curtiss C-76 Caravan, the Waco design was made out of wood and featured a high wing and rear loading door/ramp. The tadpole-shaped aircraft had the empennage cantilevered over the aft ramp on a boom. The undercarriage was fixed as well. Using the same engines as the C-47, the Army placed orders for 13 pre-production examples and 240 production aircraft. However, again, like the Conestoga and Caravan, the anticipated shortage of aluminum never occurred and the C-62 was canceled. Allegedly the first aircraft was nearing completion at the time of the cancellation, but this hasn't been confirmed. 

Fairchild C-82 Packet at the National Museum of the USAF

The last aircraft that sprang from the 1941 call was the Fairchild C-82 Packet. Designed by Fairchild's chief designer, Armand J. Thieboldt, the original plans were for the C-82 to be made of wood. Like the other three aircraft, the Packet had a high wing and tricycle landing gear to allow for a level main cargo deck that was unobstructed. The flight deck was raised above the cargo deck and a twin boom layout was chosen to leave the tail area completely clear for straight though loading and unloading. With the fortunes of war shifting in favor of the Allies in the summer of 1942 after the Battle of Midway and an expansion of domestic aluminum production eased shortage concerns, the USAAF requested that Fairchild abandon wood for the C-82 and go with aluminum. Of four aircraft designs for a C-47 replacement, the decision to switch to aluminum more than likely contributed to the reasons why the Packet did get to production and service. Being the last submission probably saved the design as it was also redesigned to take a more powerful engine, the Pratt & Whitney R-2800 Double Wasp instead of using the same engines as the C-47. As a result, the C-82 had the highest cargo payload of the four designs. 

First flight took place on 10 September 1944 at Fairchild's plant in Hagerstown, Maryland. The first series of flights were so encouraging that the USAAF ordered 100 C-82s just 18 days after the first flight. With an eye towards the coming invasion of Japan, North American's Dallas plant was planned for an additional 1000 C-82s on top of an additional 100 from Fairchild for a total of 200 from the Hagerstown plant. The first C-82s were delivered to the USAAF in June 1945 but the sudden end of the war with the Japanese surrender in September 1945 resulted in the cancelation of the North American production run at Dallas with only just three Dallas-built C-82s being built. Despite the drawdown in US military forces, the C-82 Packet was the C-47 replacement the USAAF wanted and the 200-aircraft order from the Fairchild plant in Maryland stood to fulfill postwar airlift requirements. Five C-82s participated in the Berlin Airlift, bringing in heavy equipment and vehicles that couldn't be accommodated onto the Douglas C-54 Skymasters. Operational use of the C-82 revealed several shortcomings, the most concerning of which was that with a full load, a C-82 with one engine out couldn't maintain level flight. Thieboldt and his team at Fairchild went about improving the C-82 design first by incorporating more powerful engines in the form of the Pratt & Whitney R-4360 Wasp Major as well as a host of other improvements to satisfy the newly-independent US Air Force's concerns. Originally designated XC-82B, the changes were so significant that a new designation was assigned to the upgrade which became the C-119 Flying Boxcar. The first flight was made on 17 December 1947. As C-119s were delivered to USAF units, the C-82s were retired. A total of 220 Packets were built. Quite a few Packets had long civilian careers, but that's a story for future blog article! 

Source: The Legacy of the DC-3 by Henry M. Holden. Wind Canyon Publishing, 1996, pp 141-148. Information also from National Museum of the USAF, Wikipedia and www.c82packet.com. Photos: Wikipedia, Australian War Memorial, National Museum of the USAF. C-62 wind tunnel model from R/C Groups forum.

Rockwell Builds the Shuttle by Farming Out the Work

The Grumman Shuttle Orbiter design

On 26 July 1972, NASA announced that Rockwell International had been selected as the prime contractor for the Space Shuttle (specifically the Shuttle Orbiter) after an intense competition with Lockheed, Grumman, and McDonnell Douglas. Each contractor proposal also had to detail management of the complex program as well as its technical aspects and the lengthy proposals then went to a specially convened selection board at NASA which evaluated each submission. The top two proposals belonged to Rockwell and Grumman and showcased the effect that a good management proposal could have in winning the competition. From a technical standpoint, NASA scored the Grumman proposal the best, with Rockwell's orbiter design coming in second. Rockwell's submission, however, impressed the NASA selection board with its management system. With the cost overruns on several military programs like the Lockheed C-5 Galaxy on everyone's mind, Rockwell's management proposal stressed cost controls for what was to be the biggest aviation contract in years. With a technical design not much more inferior that the Grumman design, Rockwell was awarded the contract. 

In the industry slump as Vietnam was winding down, the Orbiter contract was a very big prize for any firm that could clinch the award. At the time of the selection, Rockwell had 6,200 employees in their Space Division and with the award, plans were in place to hire as many as 16,000 by 1975. Priority would given to anyone who had worked on the Apollo program. Despite the buoyant mood at Rockwell, things were considerably more glum at the losing contenders, Grumman, Lockheed, and McDonnell Douglas. Grumman had been a mainstay of the US space program from its early days, best known for its work on the Apollo Lunar Module. Company officials made plans for Grumman to be out of the space business by December 1972 along with the attendant layoffs. 

McDonnell Douglas (via McDonnell) had built the Mercury and Gemini spacecraft and was in the midst of winding down its work as the prime contractor for Skylab. The company was also suffering from a downturn in the world commercial aviation market that was affecting most greatly its Douglas DC-9 program. 11,000 layoffs were planned at McDonnell Douglas by 1973.

While Lockheed didn't have as prominent a role in the US manned spaceflight program in the 1960s as McDonnell Douglas or Grumman, their expertise in high speed flight as well as thermal protection systems was unparalleled in the industry at the time. 

Rockwell, however, recognized two realities that came with winning the Shuttle Orbiter contract. The first one was the limitations of its in-house expertise. Quite simply, Rockwell would need other aerospace companies for their skills and expertise to bring the Orbiter to fruition. The second reality was a bit more prosaic but nonetheless vital. Keep in mind that in the early 1970s there was an atmosphere of budget austerity and NASA was no less exempt from financial realities than any other government agency at the time. Subcontracting work on the Orbiter to other companies in effect would spread the footprint of the endeavor across the districts of multiple Congressional representatives who would be routinely voting on NASA's budgetary allocations for the Space Shuttle program. Subcontracts were a common way as well in the industry of building goodwill- by farming out work to competitors and keeping them active and in business, today's winner might one day become tomorrow's loser on a another program and could hope for subcontract work from a rival. 

Rockwell planned to subcontract at least 53% of the work on the Shuttle Orbiter and this had NASA's blessing as a means of preserving the American industrial base for spaceflight. Just weeks after winning the contract as the prime, Rockwell was already conducting seminars across the nation for potential subcontractors. By March 1973 Rockwell began selecting subcontractors for the program with NASA's approval. Grumman would work on the delta wing, McDonnell Douglas got the OMS (Orbital Maneuvering System), Fairchild Republic got the vertical fin, and the Convair Division of General Dynamics got the mid-fuselage/payload bay. Rockwell would be responsible for the nose and crew compartment as well as the aft fuselage that would house the three Rocketdyne SSME (Space Shuttle Main Engine) packages. Lockheed would get the External Tank while Thiokol got the contract for the SRB (Solid Rocket Booster). 

By the summer of 1975, 34,000 workers across 47 states and a broad host of companies across the American aerospace industry were working on the Space Shuttle program. The peak would be in 1977 with 47,000 workers. The post-Vietnam slump, the Space Shuttle program was very much the crown jewel of the US aviation industry. 

Source: Development of the Space Shuttle 1972-1981: History of the Space Shuttle, Volume Two by T.A. Heppenheimer. Smithsonian Institution Press, 2002. Illustration: Aerospace Projects Review

The Fairchild XNQ-1/T-31 Trainer

In USAF markings as the T-31

As the Second World War began to wind down with victory in Europe established and the end of the Pacific War on the horizon, the US Navy set out to issue specifications for a replacement for the basic and primary aircraft trainers that were used during the war (like the PT-19 or the BT-13, PT standing for "Primary Trainer" and BT standing for "Basic Trainer in the Navy lexicon) as well as the North American SNJ/T-6 Texan. These specifications were released to the industry on 26 April 1945 by the Bureau of Aeronautics (BuAer). Three companies entered designs- Temco entered the T-35 Buckaroo which was adapted from the Globe Swift general aviation aircraft, Beechcraft entered the T-34 Mentor which was a tandem seat adaptation of the Bonanza and Fairchild entered a custom-designed aircraft that had the Navy designation XNQ and the later USAF designation T-31. History, of course, shows that the Beech Mentor won the competition and one of it's strong points was its tricycle undercarriage layout compared to the taildragger layout of both the Buckaroo and the XNQ. For the forward thinking armed services, taildragging aircraft were obsolete. 

Fairchild's chief engineer, Armand Thiebolt, had already established a name for himself having designed a number of training aircraft during the war, from the PT-19 Cornell to the AT-21 Gunner. His work on the XNQ was based on his own experiences and what he felt was a balance between state of the art and simplicity. Registered with a civilian tail number N5726, the first XNQ, built at Fairchild's Hagerstown, Maryland, plant, made its first flight there on 10 February 1947 with Fairchild's chief test pilot, Richard Hansen, at the controls. The 20-minute maiden flight was uneventful and showed only some simple rework of the aileron tabs were necessary. After a series of company test flights, the XNQ was delivered to the US Navy at Anacostia, Washington for formal evaluation. After an initial series of flights in the Washington DC area, the flight test program continued at NAS Patuxent River after which the aircraft returned to Fairchild to prepare it for evaluation by the USAF as the T-31. 

By this point the second aircraft had been completed and both XNQs as T-31s were flown to Randolph AFB outside of San Antonio, Texas, for their formal USAF evaluation in a fly-off with both the Beech and Temco candidates. At the time the USAF also considered the De Havilland Canada DHC-1 Chipmunk as well as the British Boulton Paul Balliol, but both were quickly eliminated from consideration, leaving Fairchild, Beech, and Temco remaining in the USAF evaluation. Like the US Navy, the USAF selected the Beech T-34 Mentor, again, its tricycle landing gear layout being one of its strong points. It was the second rejection of the Fairchild design. The aircraft was passed on to the US Navy where it was flown by student test pilots at the US Navy's Test Pilot School at NAS Patuxent River and after a gear up landing that resulted in only minor damage in 1953, the Navy declared the unique aircraft surplus to its needs after it had only amassed just over 1,000 flight hours. 

The wing commander for the National Capital Wing of the Civil Air Patrol arranged to take ownership of the XNQ and in October 1953 the aircraft was repaired at NAS Patuxent River before being flown to a small airfield south of Alexandria, Virginia where it was stationed for the next 2 years, only clocking 12 flight hours in that time period. Part of the problem with the XNQ wasn't its performance or handling, but that its wingspan was just over a foot too wide for the standard 40-foot hangar at the airfield and it ended up spending most of its time outdoors which adversely affected its condition. In 1955 the aircraft was ferried to Rockville, Maryland, but again, was stored outdoors which resulted in further deterioration. When that small airfield was closed, the Fairchild was abandoned in situ. 

In her original US Navy markings

John St. Clair, the operations officer of the Congressional Squadron of the Civil Air Patrol, trucked aircraft to his home 8 miles away to try and save it given its unique history. He later assumed formal ownership of the aircraft to keep it from going to the junkyard. Fast forward to 1978, the aircraft is still on the St. Clair farm in rural Maryland and Armand Thiebolt's son visited John St. Clair and asked about purchasing the aircraft, the deal of which fell through. Later, Robert Taylor, the founder of the Antique Airplane Association, asked St. Clair if he would done the XNQ to a museum, which he agreed to and a crew from the association trucked what was left of the aircraft to Waco, Texas with plans of restoring her to flight status. The history of the XNQ took a new turn after its arrival in Waco when general aviation pilot Don Pellegrino and his wife were weathered in at the airport and he found the XNQ in storage in a hangar and approached Taylor about purchasing the aircraft. 

While negotiations proceeded, the aircraft was moved to Oklahoma City in 1982 but still no restoration work had started. At a fly-in in Iowa, Taylor approached Pellegrino and told him "Make me an offer I can't refuse" and with that, Pellegrino become the XNQ's new owner for $800. In September that year Pellegrino trucked the aircraft to his farm in Iowa and began restoration work in earnest. After ten years of working on it in his free time, the XNQ made its second maiden flight on 1 June 1992, the first time the aircraft had flown since 1955! Pellegrino flew the 25 FAA-required hours of flight testing himself and since then he has since moved to Rhome, Texas, just outside of the Dallas-Fort Worth area and has flown the XNQ to airshows around the country. And yes, she still has her same tail number of N5726 after all these years!

Bill Spidle has three pages of detailed photographs of a walk around of the XNQ.

Source: Air Enthusiast, No. 117, May/June 2005. "Their Loss, My Gain: Fairchild's XNQ-1- Twice Rejected for Service" by Gilles Auliard, p78-79. Photos: US Naval Test Pilot School Alumni.

Operation Ranch Hand and Agent Orange

Noted aviation historian Walter Boyne described Operation Ranch Hand as "a heart-rending example of how good airmen can be forced to do unpleasant work when it is determined that the war effort demands it." There are few events in aviation history that evoke strong debates even to this day as those that surround the nine year use by the US military of the defoliant Agent Orange in Vietnam. The aerial spraying of herbicides was used initially in the United States for weed control but was on a strictly limited basis in the immediate post-war period. The first "military" use of aerial herbicide spraying came during the Communist insurgency in Malaysia during the 1950s when the British used it on a limited basis to keep communication lines through the jungle clear.

The British use of air-delivered defoliants was cited by by proponents in 1961 in the proposal presented for President Kennedy's consideration. Supported by the Secretary of Defense, Robert McNamara, the requisite approvals were also secured from not just the President but also President Ngo Dinh Diem and the government of South Vietnam. Some in the administration had raised the issue that use of the defoliants might be considered chemical warfare, but McNamara felt that operational necessity to reduce Viet Cong ambushes and hideouts in South Vietnam made the risk worthwhile. On 3 November 1961 McNamara authorized the use of defoliants in South Vietnam to combat the Viet Cong ambushes on US and ARVN units.

The USAF already had a limited ability already present for the aerial spraying of defoliants as part of its public service work on mosquito-control projects in the southeastern United States. At the end of World War II, a Special Aerial Spray Flight (SASF) was established at Langley AFB in Virginia to undertake mosquito-control spraying. Activated in 1961 for Operation Ranch Hand, the SASF received six Fairchild C-123 Providers for modification into aerial sprayers. Inside the cargo hold of the Provider would be a 1,000 gallon tank connected to spray equipment mounted on the wings that could deliver the herbicides. To the surprise of the commander of the SASF, he found no shortage of volunteer pilots to fly the first Ranch Hand missions despite the proviso that they would wear civilian clothes, fly unmarked aircraft, be on temporary duty to Vietnam for extended periods of time and if shot down and captured, would not be acknowledged as USAF personnel.

There were several different herbicide options, each differing in the proportions of different chemicals present in the mix. Each option was given a color code name. Some of the options available included Agent White, Agent Blue, Agent Purple, but the most widely used option would become infamous- Agent Orange.

Once the first six C-123 Providers were modified, they deployed to South Vietnam and arrived in-theater in January 1962. The aircraft fleet ebbed and flow with the war, peaking at 25 C-123s in 1969. Over 20 million gallons of Agent Orange would be sprayed over 6 million acres in South Vietnam. Unlike a lot of other military experiments in Vietnam that were failures, the use of Agent Orange did work in denying the Viet Cong jungle cover in strategic areas of the country. After a significant decrease in the number of ambushes on US Army/ARVN units in the first year of use, Defense Secretary McNamara authorized an expansion of Operation Ranch Hand to include areas of the Ho Chi Minh Trail used to infiltrate supplies and personnel into South Vietnam, and more significantly, to use Agent Orange for the destruction crops in Viet Cong strongholds to try and limit their food supplies.

The Ranch Hand effort expanded significantly in 1962 as a result as the C-123s wore South Vietnamese Air Force markings (and later in the war, full USAF markings). In fact, the first US aircraft shot down in Vietnam was a Ranch Hand C-123 on 2 February 1962, killing all three crew.

The first protests by North Vietnam were echoed by the Soviet Union and China in 1961 but met with a muted response by other nations. But criticism grew both in the United States and abroad as the program was expanded in 1962 to include crop destruction as the Viet Cong had successfully blended into the local population and as a result, the crops of many "friendly" South Vietnamese were also destroyed. By 1965 scientists in the United States were protesting the use of Agent Orange and the banner was subsequently picked up by the media and the anti-war movement of the day. Three years later, President Nguyen Van Thieu of South Vietnam felt that Operation Ranch Hand was counterproductive but his concerns were overridden by a 1969 report prepared by the American ambassador to South Vietnam with a committee he appointed that showed that the use of the three main herbicides, Agents Orange, Blue, and White, were not harmful. Ambassador Ellsworth Bunker's report quite obviously had the opposite effect and further inflamed the controversy further. Finally, on 22 December 1970 Secretary of Defense Melvin Laird advised President Richard Nixon that any herbicide use should conform to delivery and use standards in place in the United States which effectively ended the use of Agent Orange in South Vietnam. The last Ranch Hand flight flew on 7 January 1971.

Since the end of Operation Ranch Hand, millions of dollars in claims have been paid out by the manufacturer of Agent Orange and the Veterans Administration for the deleterious health consequences of the widespread spraying of the herbicide for nine years. To this day health effects are still being seen in even in individuals a generation removed from those originally exposed to Agent Orange. In fact, when the National Museum of the United States Air Force in Dayton, Ohio, was to put on display a C-123 Provider that had taken more battle damage than any other of its type, it was subject to a political and legal controversy by local environmentalists that resulted in the aircraft being sealed up for display despite the fact no traces of Agent Orange could be found in the airframe.

Source: Beyond the Wild Blue- A History of the United States Air Force, 1947-2007, Second Edition by Walter J. Boyne. Thomas Dunne Books/St. Martin's Press, 2007, p157-159.